Diclofenac is an acetic acid nonsteroidal anti-inflammatory drug (NSAID) with analgesic and antipyretic properties. Diclofenac is used to treat pain, dysmenorrhea, ocular inflammation, osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, and actinic keratosis. The antiinflammatory effects of diclofenac are believed to be due to inhibition of both leukocyte migration and the enzyme cylooxygenase (COX-1 and COX-2 or prostaglandin G/H synthase 1 and 2), leading to the peripheral inhibition of prostaglandin synthesis. As prostaglandins contribute to pain perception, inhibition of their synthesis confers analgesic effects to diclofenac. Antipyretic effects may be due to action on the hypothalamus, resulting in peripheral dilation, increased cutaneous blood flow, and subsequent heat dissipation.